Passenger comfort is an important consideration for any passenger transit vehicle. Much consideration is given to the suspension, the seating and the power delivery in order to ensure a smooth and comfortable ride for the passengers. However, when considering passenger comfort, another important criterion to take into consideration is the transit vehicle's ventilation system. Many transit vehicles operate in climates that can become quite hot in the summer time. When weather temperatures increase, transit vehicles can become hot, stuffy and suffocating, which can greatly detract from passenger comfort. This is particularly true during rush hours, when the passenger load within the transit vehicles is high.
In order to address the issue of passenger comfort when the weather gets hot, many public transit systems have installed air conditioning units into their transit vehicles. While air conditioning is effective at keeping temperatures within the transit vehicles comfortable, a deficiency with these systems is that they are expensive to purchase and to operate.
Other known ventilation systems that are used in transit vehicles operate with large axial fans in the ceiling that direct air from outside the transit vehicle into the passenger compartment of the transit vehicle. A deficiency with these ventilation systems is that they generally concentrate the supply of air in a given location, such that not all the passengers benefit from the farming effect. A further deficiency with these existing ventilation systems is that the fan's ability to move air decreases as the vehicle accelerates. Furthermore they do not adjust dynamically to increasing passenger discomfort.
In light of the above, it can be seen that there is a need in the industry for an improved ventilation system for passenger transit vehicles that is able to alleviate, at least in part, the deficiencies of existing systems.